For example, in the manufacturing process for a semiconductor product, a semiconductor wafer is placed on a temperature-controlling stage, which has heating and cooling capabilities, and processing, such as applying a coating of photoresist material to this semiconductor wafer, and subsequently subjecting it to etching, is carried out while adjusting the temperature of the semiconductor wafer using the temperature-controlling stage. In the preparatory phase prior to commencing the above-mentioned semiconductor manufacturing process, control parameters for the temperature-controlling stage must be set so as to uniformly control the temperature of a semiconductor wafer to the optimum level. In this setting process, a temperature-measuring semiconductor wafer on which temperature sensors are disposed in a plurality of locations (hereinafter, referred to as a temperature sensing substrate) is placed on the temperature-controlling stage, and the temperature-controlling stage is test operated using the given control parameters, heating and cooling operations are performed, the temperature of the temperature sensing substrate is measured at these times, and a determination is made as to whether or not a measured temperature is optimum. If these results are not optimum, the control method (for example, the various parameters, such as target temperature and control operations) are modified, and the above-mentioned test operation is performed once again using the modified control parameters.
When the temperature sensing substrate is placed on the temperature-controlling stage, and the temperature is measured like this, it is important that the temperature of the temperature sensing substrate be measured as accurately as possible. As conventional methods for measuring the temperature of the temperature sensing substrate, a method, whereby a temperature sensor is attached in contact with the top of the temperature sensing substrate and a signal is captured from the temperature sensor via a wire lead, and a method, whereby a resistor and a lead make close contact as a temperature sensor on top of the temperature sensing substrate and a signal is captured from the lead terminal, which is placed on the surface of this temperature sensing substrate via a wire lead, are disclosed in Japanese Laid-open Patent No. 2000-241257.
According to the methods disclosed in Japanese Laid-open Patent No. 2000-241257, the sensor and lead on top of the temperature sensing substrate can be patterned using screen printing. However, when printing is used to pattern the sensor and lead on top of the temperature sensing substrate, since the lead terminal is on the wafer, this results in the need to link the lead terminal on the temperature sensing substrate to a wire lead. Further, since there is a plurality of wire leads on top of the temperature sensing substrate, these wire leads disturb the temperature distribution and flow of air on the temperature sensing substrate, thereby affecting the temperature of the temperature sensing substrate. Further, because cleaning becomes difficult, the degree of cleanliness of the entire device deteriorates.
Also, there are instances when the temperature of the temperature-controlling stage should be measured, either during the above-mentioned setting process, or during the semiconductor manufacturing process for processing a semiconductor wafer. In this case, the temperature measurement capabilities of the above-mentioned conventional temperature sensor decline for the same reasons as cited hereinabove.
An object of the present invention is to enable the temperature at a plurality of locations on the broad surface of an object targeted for temperature measurement to be measured with greater accuracy.
Another object of the present invention is to enable the temperature of a substrate like a semiconductor wafer to be measured with greater accuracy.